BUG: Unexpected keyword argument `maxsplit` on `rsplit` even though it is accepted in vanilla Python

Pandas version checks

• I have checked that this issue has not already been reported.

• I have confirmed this bug exists on the latest version of pandas.

• I have confirmed this bug exists on the main branch of pandas.

Reproducible Example

>>> import pandas as pd
>>> string = "foo,bar,lorep"
>>> string.rsplit(",", maxsplit=1)  # This works as expected
['foo,bar', 'lorep']
>>> pd.DataFrame({"a": [string]})["a"].str.rsplit(",", maxsplit=1)  # Use kwarg maxsplit
TypeError: rsplit() got an unexpected keyword argument 'maxsplit'
>>> pd.DataFrame({"a": [string]})["a"].str.rsplit(",", 1)  # Change kwarg to arg
0    [foo,bar, lorep]
Name: a, dtype: object

Issue Description

When using pd.Series.str.rsplit in Pandas, the accepted kwargs are inconsistent with Python’s.

Python’s str.rsplit accepts the kwarg maxsplit=, while Panda’s pd.Series.str.rsplit does not.

Expected Behavior

I expect Panda’s pd.Series.str.rsplit to behave identically to Python’s str.rsplit, this includes accepting the same kwargs, namely maxsplit= in this case.

Installed Versions

pd.show_versions()

/Users/pawlu/.virtualenvs/pandas-debug-kqdr/lib/python3.9/site-packages/_distutils_hack/__init__.py:30: UserWarning: Setuptools is replacing distutils.
  warnings.warn("Setuptools is replacing distutils.")

INSTALLED VERSIONS
------------------
commit           : 47494a48edf25d5a49b0fb5b896b454c15c83595
python           : 3.9.12.final.0
python-bits      : 64
OS               : Darwin
OS-release       : 21.4.0
Version          : Darwin Kernel Version 21.4.0: Fri Mar 18 00:45:05 PDT 2022; root:xnu-8020.101.4~15/RELEASE_X86_64
machine          : x86_64
processor        : i386
byteorder        : little
LC_ALL           : None
LANG             : en_US.UTF-8
LOCALE           : en_US.UTF-8

pandas           : 1.5.0.dev0+978.g47494a48e
numpy            : 1.22.4
pytz             : 2022.1
dateutil         : 2.8.2
setuptools       : 62.2.0
pip              : 22.1.2
Cython           : None
pytest           : None
hypothesis       : None
sphinx           : None
blosc            : None
feather          : None
xlsxwriter       : None
lxml.etree       : None
html5lib         : None
pymysql          : None
psycopg2         : None
jinja2           : None
IPython          : 8.4.0
pandas_datareader: None
bs4              : None
bottleneck       : None
brotli           : None
fastparquet      : None
fsspec           : None
gcsfs            : None
matplotlib       : None
numba            : None
numexpr          : None
odfpy            : None
openpyxl         : None
pandas_gbq       : None
pyarrow          : None
pyreadstat       : None
pyxlsb           : None
s3fs             : None
scipy            : None
snappy           : None
sqlalchemy       : None
tables           : None
tabulate         : None
xarray           : None
xlrd             : None
xlwt             : None
zstandard        : None

[MrShevan]

Hi, Can I take on me? 😃

[MarcoGorelli]

Yeah go ahead